The current owners of the Aston Martin Lagonda shares could also increase the offering by 5.7 million shares through over-allotment options, increasing the stake to a maximum of 27.5%.
"Obviously we'd all prefer no tariffs to be frank, no doubt, but the industry has to learn to adapt and it always has adapted to changes", Palmer said, referring to proposed tariffs on imported products - 60 percent of Aston Martin's parts are now imported from the EU.
In the first half of the year, Aston Martin reported a pre-tax profit of £20.8m on revenue of £449.9m.
The hotly-anticipated move is the largest IPO in the global automotive sector since Italian luxury auto giant Ferrari listed on Wall Street three years ago.
Despite an illustrious history and a brand name synonymous with 007 films, Aston Martin had struggled for decades to make a profit. It's also reviving the Lagonda name to break into the segment shared by United Kingdom rivals Rolls-Royce Motors and Bentley.
Analysts had previously shown scepticism the manufacturer, based in Graydon, England, would reach its previous goal of as much as £5.07 billion.
Aston Martin, whose top-end cars are cherished by Hollywood actors, global sports stars and British royalty, is selling 25 percent of its share capital or 57 million shares.
But under Mr Palmer, a former Nissan executive, the company has been broadening its product range and has moved into new areas. While the UK's post- Brexit automotive industry is one of the sectors most exposed to potential trade hurdles, the company is "well insulated" in the case talks break down and Britain leaves the bloc without a trade deal, Palmer said last month. The CEO said Aston wanted "investors looking for the long term and in choosing the price we have been able to select a very awesome book" of them.
The listing marks the first IPO of a United Kingdom carmaker in more than three decades, since Jaguar was spun into an independent company under Margaret Thatcher's government in 1984.
The company is owned mostly by investors in Kuwait and Italy. "I was not involved", he said.